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java.lang.Objectorg.apache.commons.collections4.map.AbstractIterableMap<K,V>
org.apache.commons.collections4.map.AbstractMapDecorator<K,V>
org.apache.commons.collections4.map.LazyMap<K,V>
org.apache.commons.collections4.map.LazySortedMap<K,V>
public class LazySortedMap<K,V>
Decorates another SortedMap
to create objects in the map on demand.
When the LazyMap.get(Object)
method is called with a key that does not
exist in the map, the factory is used to create the object. The created
object will be added to the map using the requested key.
For instance:
Factory<Date> factory = new Factory<Date>() { public Date create() { return new Date(); } } SortedMap<String, Date> lazy = LazySortedMap.lazySortedMap(new HashMap<String, Date>(), factory); Date date = lazy.get("NOW");After the above code is executed,
date
will refer to
a new Date
instance. Furthermore, that Date
instance is mapped to the "NOW" key in the map.
Note that LazySortedMap is not synchronized and is not thread-safe.
If you wish to use this map from multiple threads concurrently, you must use
appropriate synchronization. The simplest approach is to wrap this map
using Collections.synchronizedSortedMap(java.util.SortedMap
. This class may throw
exceptions when accessed by concurrent threads without synchronization.
This class is Serializable from Commons Collections 3.1.
Nested Class Summary |
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Nested classes/interfaces inherited from interface java.util.Map |
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Map.Entry<K,V> |
Field Summary |
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Fields inherited from class org.apache.commons.collections4.map.LazyMap |
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factory |
Constructor Summary | |
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protected |
LazySortedMap(SortedMap<K,V> map,
Factory<? extends V> factory)
Constructor that wraps (not copies). |
protected |
LazySortedMap(SortedMap<K,V> map,
Transformer<? super K,? extends V> factory)
Constructor that wraps (not copies). |
Method Summary | ||
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Comparator<? super K> |
comparator()
|
|
K |
firstKey()
|
|
protected SortedMap<K,V> |
getSortedMap()
Gets the map being decorated. |
|
SortedMap<K,V> |
headMap(K toKey)
|
|
K |
lastKey()
|
|
static
|
lazySortedMap(SortedMap<K,V> map,
Factory<? extends V> factory)
Factory method to create a lazily instantiated sorted map. |
|
static
|
lazySortedMap(SortedMap<K,V> map,
Transformer<? super K,? extends V> factory)
Factory method to create a lazily instantiated sorted map. |
|
SortedMap<K,V> |
subMap(K fromKey,
K toKey)
|
|
SortedMap<K,V> |
tailMap(K fromKey)
|
Methods inherited from class org.apache.commons.collections4.map.LazyMap |
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get, lazyMap, lazyMap |
Methods inherited from class org.apache.commons.collections4.map.AbstractMapDecorator |
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clear, containsKey, containsValue, decorated, entrySet, equals, hashCode, isEmpty, keySet, put, putAll, remove, size, toString, values |
Methods inherited from class org.apache.commons.collections4.map.AbstractIterableMap |
---|
mapIterator |
Methods inherited from class java.lang.Object |
---|
clone, finalize, getClass, notify, notifyAll, wait, wait, wait |
Methods inherited from interface java.util.Map |
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clear, containsKey, containsValue, entrySet, equals, get, hashCode, isEmpty, keySet, put, putAll, remove, size, values |
Constructor Detail |
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protected LazySortedMap(SortedMap<K,V> map, Factory<? extends V> factory)
map
- the map to decorate, must not be nullfactory
- the factory to use, must not be null
IllegalArgumentException
- if map or factory is nullprotected LazySortedMap(SortedMap<K,V> map, Transformer<? super K,? extends V> factory)
map
- the map to decorate, must not be nullfactory
- the factory to use, must not be null
IllegalArgumentException
- if map or factory is nullMethod Detail |
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public static <K,V> LazySortedMap<K,V> lazySortedMap(SortedMap<K,V> map, Factory<? extends V> factory)
K
- the key typeV
- the value typemap
- the map to decorate, must not be nullfactory
- the factory to use, must not be null
IllegalArgumentException
- if map or factory is nullpublic static <K,V> LazySortedMap<K,V> lazySortedMap(SortedMap<K,V> map, Transformer<? super K,? extends V> factory)
K
- the key typeV
- the value typemap
- the map to decorate, must not be nullfactory
- the factory to use, must not be null
IllegalArgumentException
- if map or factory is nullprotected SortedMap<K,V> getSortedMap()
public K firstKey()
firstKey
in interface SortedMap<K,V>
public K lastKey()
lastKey
in interface SortedMap<K,V>
public Comparator<? super K> comparator()
comparator
in interface SortedMap<K,V>
public SortedMap<K,V> subMap(K fromKey, K toKey)
subMap
in interface SortedMap<K,V>
public SortedMap<K,V> headMap(K toKey)
headMap
in interface SortedMap<K,V>
public SortedMap<K,V> tailMap(K fromKey)
tailMap
in interface SortedMap<K,V>
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